Image processor and image processing method

ABSTRACT

According to one embodiment, an image processor includes a generator, a high-resolution image generator, a separator, a texture generator, and a combiner. The generator compresses an input image to generate a low-resolution image. The high-resolution image generator generates, from the input image, a high-resolution image that is higher in resolution than the input image. The separator separates the low-resolution image generated by the generator into a texture component image and a frame component image. The texture generator generates texture component from the texture component image and the frame component image separated by the separator. The combiner combines the texture component generated by the texture generator with the high-resolution image generated by the high-resolution image generator to generate an output image.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2010-267771, filed on Nov. 30, 2010, theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to an image processor andan image processing method.

BACKGROUND

There have been known image processors that perform image processing togenerate a high-resolution output image from an input image.

In this type of image processor, image processing is a heavy load andtakes a lot of memory.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

A general architecture that implements the various features of theinvention will now be described with reference to the drawings. Thedrawings and the associated descriptions are provided to illustrateembodiments of the invention and not to limit the scope of theinvention.

FIG. 1 is an exemplary block diagram schematically illustrating thehardware configuration of a television receiver having an imageprocessor mounted thereon according to a first embodiment;

FIG. 2 is an exemplary block diagram of the image processor in the firstembodiment;

FIG. 3 is an exemplary flowchart of image processing performed by theimage processor in the first embodiment;

FIG. 4 is an exemplary block diagram of an image processor according toa second embodiment;

FIG. 5 is an exemplary flowchart of image processing performed by theimage processor in the second embodiment; and

FIG. 6 is an exemplary block diagram of a conventional image processor.

DETAILED DESCRIPTION

In general, according to one embodiment, an image processor comprises agenerator, a high-resolution image generator, a separator, a texturegenerator, and a combiner. The generator is configured to compress aninput image to generate a low-resolution image. The high-resolutionimage generator is configured to generate, from the input image, ahigh-resolution image that is higher in resolution than the input image.The separator is configured to separate the low-resolution imagegenerated by the generator into a texture component image and a framecomponent image. The texture generator is configured to generate texturecomponent from the texture component image and the frame component imageseparated by the separator. The combiner is configured to combine thetexture component generated by the texture generator with thehigh-resolution image generated by the high-resolution image generatorto generate an output image.

Exemplary embodiments will be described in detail below with referenceto the accompanying drawings.

The image processor of the embodiments is configured to be mounted on anelectronic device, and is described herein by way of example as beingapplied to a television receiver.

FIG. 1 is a block diagram schematically illustrating the hardwareconfiguration of a television (TV) receiver 1 having an image processor10 mounted thereon according to a first embodiment.

As illustrated in FIG. 1, the TV receiver 1 comprises a tuner 2, asignal processor 3, a display device 4, a controller 5, and a powersupply 6.

The tuner 2 receives content data from a broadcast station via anantenna, and outputs it to a storage module (not illustrated) and thecontroller 5.

The signal processor 3 converts content data received from the tuner 2or an external storage module (not illustrated) into a video signal andan audio signal. The signal processor 3 comprises the image processor 10and an audio processor (not illustrated). The image processor 10performs predetermined image processing on the video signal (inputimage) to generate a high-resolution output image and outputs it to thedisplay device 4. Meanwhile, the audio processor performs predeterminedprocessing on the audio signal and outputs it to a speaker (notillustrated).

The display device 4 displays video. The display device 4 may comprise,for example, a liquid crystal display (LCD).

The controller 5 comprises a central processing unit (CPU), a read onlymemory (ROM), a random access memory (RAM), and the like. The controller5 controls the overall operation of the TV receiver 1.

The power supply 6 supplies power from, for example, a commercial powersource to each load.

FIG. 2 is a block diagram of the image processor 10 of the firstembodiment.

Roughly, the image processor 10 performs predetermined image processingto add a high-resolution component (texture component) to a provisionalhigh-resolution image (base image) generated from an input image,thereby improving the texture of the image displayed on the displaydevice 4. In the following, an example will be described in which theimage processor 10 generates an output image in a different size from acorresponding input image.

As illustrated in FIG. 2, the image processor 10 comprises a provisionallow-resolution image generator 11, a frame/texture separator 12, aprovisional high-resolution image generator 13, a texture generator 14,a combiner 15, and an image blur prevention module 16.

The provisional low-resolution image generator 11 compresses images of Uand V chrominance (hue, color) components except Y luminance(brightness) component of an input image to generate low-resolutionimages. Examples of the input image include a semi-high definition (HD)image having a resolution of 1440×1080 in YUV420 format and the like.

The frame/texture separator 12 separates each of the provisionallow-resolution images of UV (chrominance) components generated by theprovisional low-resolution image generator 11 and an image of Y(luminance) component of the input image into a texture component imageand a frame component image.

The provisional high-resolution image generator 13 generates aprovisional high-resolution image (base image) from the input image. Theprovisional high-resolution image has a higher resolution than the inputimage. If the output image is in the same size as the input image, theprovisional high-resolution image (base image) is not generated. Theprovisional high-resolution image generator 13 may comprise, forexample, a cubic convolution filter.

The texture generator 14 generates texture component (high-frequencycomponent) to be combined with the provisional high-resolution imagegenerated by the provisional high-resolution image generator 13 from thetexture component image of Y component and frame component images of Y,U, and V components separated by the frame/texture separator 12. Thetexture component to be combined refers to texture component highlysimilar to a predetermined area (each attention point) of the outputimage in YUV420 format or the like. The texture generator 14 furtherreceives the provisional high-resolution image of Y (luminance)component generated by the provisional high-resolution image generator13 to reduce or eliminate noise around the edge.

The combiner 15 combines the texture component generated by the texturegenerator 14 with the high-resolution image generated by the provisionalhigh-resolution image generator 13, thereby generating an output imagein YUV420 format or the like.

The image blur prevention module 16 prevents blur (image blur) in thehigh-resolution image of Y (luminance) component generated by theprovisional high-resolution image generator 13. The image blurprevention module 16 may comprise, for example, an unsharp mask (USM)filter. The valid/invalid is determined by option, and the default maybe set to invalid. The image processor 10 need not necessarily comprisethe image blur prevention module 16.

The operation of the image processor 10 will be described.

FIG. 3 is a flowchart of image processing performed by the imageprocessor 10.

As illustrated in FIG. 3, when the image processor 10 receives an inputimage in YUV420 format or the like (S1), the provisional low-resolutionimage generator 11 compresses images of UV (chrominance) components ofthe input image to a predetermined size, thereby generating provisionallow-resolution images (S2).

Subsequently, the frame/texture separator 12 separates each of theprovisional low-resolution images of UV (chrominance) componentsgenerated by the provisional low-resolution image generator 11 and animage of Y (luminance) component of the input image into a texturecomponent image and a frame component image (S3). More specifically, theframe/texture separator 12 first extracts texture component and thengenerates frame component based on the texture component data.

Next, the provisional high-resolution image generator 13 expands theinput image into an output size to generate a provisionalhigh-resolution image (base image) (S4).

After that, the texture generator 14 generates texture component(high-frequency component) highly similar to a predetermined area (eachattention point) of the output image in YUV420 format or the like fromthe texture component image of Y component and frame component images ofY, U, and V components separated by the frame/texture separator 12, andthe provisional high-resolution image (base image) of Y (luminance)component received from the provisional high-resolution image generator13 (S5).

More specifically, at S5, the texture generator 14 detects a texturepattern highly similar to each attention point according to output imagesize. The texture generator 14 stores the value of texture componentcorresponding to the detection point as provisional data. To detect ahighly similar texture pattern, the texture generator 14 sets apredetermined area (for example, 16×16 pixels) surrounding eachattention point in the output image as a search range. From apredetermined area of each search point (for example, 16 pixels) and apredetermined area of each attention point (for example, 16 pixels), thetexture generator 14 calculates the average of the sum of absolutedifferences (SAD) with respect to valid data. The texture generator 14detects a point where the average is the smallest in the search range asa highly similar texture pattern. In this manner, the texture generator14 generates provisional data for the entire frame.

Thereafter, the combiner 15 combines the texture component (provisionaldata) generated by the texture generator 14 with the provisionalhigh-resolution image (base image) of Y (luminance) component generatedby the provisional high-resolution image generator 13, therebygenerating an output image in YUV420 format or the like, i.e., ahigh-resolution image with fine texture (S6).

As described above, in the image processor 10 of the first embodiment,an input image is compressed into a low-resolution image and then fed tothe frame/texture separator 12. Therefore, compared with a conventionalconfiguration illustrated in FIG. 6, processing load on theframe/texture separator 12 is reduced, which reduces processing load onthe entire image processor 10. Moreover, the image processor 10 (forexample, the frame/texture separator 12) uses less memory.

According to the first embodiment, the image processor 10 does notcompress an image of Y (luminance) component among components of aninput image because human visual is sensitive to Y component. The imageprocessor 10 compresses images of only UV (chrominance) components towhich human visual is less sensitive, and feeds the images to theframe/texture separator 12. Thus, it is possible to prevent or reducehuman-perceptible degradation of image quality.

According to the first embodiment, since processing load on the entireimage processor 10 is reduced, it is possible to avoid or reduceunfulfilled conditions (unachieved performance) such as, for example,that 60 frame images cannot be displayed per second on the displaydevice 4 not to make the user feel uncomfortable.

A second embodiment will be described.

FIG. 4 is a block diagram of an image processor 100 according to thesecond embodiment. The image processor 100 can replace the imageprocessor 10 mounted on the TV receiver 1 illustrated in FIG. 1.

As illustrated in FIG. 4, the image processor 100 comprises aprovisional low-resolution image generator 101, a frame/textureseparator 102, a provisional high-resolution image generator 103, atexture generator 104, a combiner 105, an image blur prevention module106, and a reference texture image generator 107.

The image processor 100 is different from the image processor 10 of thefirst embodiment in that it further comprises the reference textureimage generator 107. In addition, the provisional low-resolution imagegenerator 101, the frame/texture separator 102, and the texturegenerator 104 operate differently from those of the first embodiment. Adescription will not be given of the same configuration and processingas previously described for the image processor 10 of the firstembodiment.

The provisional low-resolution image generator 101 compresses images ofrespective components (Y, U, and V components) of an input image inYUV420 format or the like to generate low-resolution images. That is,differently from the provisional low-resolution image generator 11, theprovisional low-resolution image generator 101 compresses also an imageof Y (luminance) component of the input image and generates alow-resolution image.

The frame/texture separator 102 separates each of the provisionallow-resolution images of respective components (Y, U, and V components)generated by the provisional low-resolution image generator 101 into atexture component image and a frame component image.

The reference texture image generator 107 expands (restores) the texturecomponent image of a predetermined component, i.e., Y (luminance)component, separated by the frame/texture separator 102 to the inputimage, thereby generating a reference texture image. The referencetexture image generator 107 may comprise, for example, a cubicconvolution filter.

The texture generator 104 generates texture component to be combinedwith the provisional high-resolution image generated by the provisionalhigh-resolution image generator 103 from the reference texture imagegenerated by the reference texture image generator 107 and the framecomponent images of Y, U, and V components separated by theframe/texture separator 102. As with the texture generator 14 describedabove, the texture generator 104 further receives the provisionalhigh-resolution image of Y (luminance) component generated by theprovisional high-resolution image generator 103 to reduce or eliminatenoise around the edge.

The operation of the image processor 100 will be described.

FIG. 5 is a flowchart of image processing performed by the imageprocessor 100.

As illustrated in FIG. 5, when the image processor 100 receives an inputimage in YUV420 format or the like (S11), the provisional low-resolutionimage generator 101 compresses images of respective components (Y, U,and V components) of the input image to a predetermined size, therebygenerating provisional low-resolution images (S12).

Subsequently, the frame/texture separator 102 separates each of theprovisional low-resolution images of respective components (Y, U, and Vcomponents) generated by the provisional low-resolution image generator101 into a texture component image and a frame component image byextracting texture component as previously described in the firstembodiment (S13).

Then, the provisional high-resolution image generator 103 expands theinput image into an output size to generate a provisionalhigh-resolution image (base image) (S14).

The reference texture image generator 107 expands (restores) the texturecomponent image of Y (luminance) component separated by theframe/texture separator 102 to the input image, thereby generating areference texture image (S15).

After that, the texture generator 104 generates texture component highlysimilar to a predetermined area (each attention point) of the outputimage in YUV420 format or the like from the reference texture imagegenerated by the reference texture image generator 107 and the framecomponent images of Y, U, and V components separated by theframe/texture separator 102 (S16). Incidentally, the texture generator104 detects a highly similar texture pattern in the same manner aspreviously described in the first embodiment.

Thereafter, the combiner 105 combines the texture component (provisionaldata) generated by the texture generator 104 with the provisionalhigh-resolution image (base image) of Y (luminance) component generatedby the provisional high-resolution image generator 103, therebygenerating an output image in YUV420 format or the like, i.e., ahigh-resolution image with fine texture (S17).

As described above, according to the second embodiment, processing loadon the entire image processor 100 can be further reduced compared to theimage processor 10 of the first embodiment. Moreover, the imageprocessor 100 uses less memory.

While the image processor 10 (100) is described above as generating anoutput image in a different size from a corresponding input image, thisis by way of example and not limitation. The image processor 10 (100)may generate an output image in the same size as a corresponding inputimage.

While the image processor 10 (100) is described above as implemented byhardware such as an electronic circuit, this is by way of example andnot limitation. Each module of the image processor 10 (100) may beimplemented by software.

While a TV receiver is exemplified above as an electronic device wherethe image processor 10 (100) is mounted, this is by way of example andnot limitation. The image processor 10 (100) may be mounted on otherelectronic devices such as recorders.

The hardware configuration of the TV receiver 1 and the image processor10 (100), input/output image format, and the like have been described byway of example only and are not limited as described herein.

The various modules of the systems described herein can be implementedas software applications, hardware and/or software modules, orcomponents on one or more computers, such as servers. While the variousmodules are illustrated separately, they may share some or all of thesame underlying logic or code.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. an image processor comprising: a generatorconfigured to compress an image of chrominance components exceptluminance component of an input image to generate a low-resolutionimage; a high-resolution image generator configured to generate, fromthe input image, a high-resolution image that is higher in resolutionthan the input image; a separator configured to separate thelow-resolution image generated by the generator into a texture componentimage and a frame component image and to separate the image of luminancecomponent of the input image into a texture component image and a framecomponent image; a texture generator configured to receive the texturecomponent image of luminance component and the frame component images ofluminance component and chrominance components separated by theseparator, and to generate texture component highly similar to each ofattention points of an image to be output; and A combiner configured tocombine the texture component generated by the texture generator withthe high-resolution image generated by the high-resolution imagegenerator to generate an output image.
 2. An image processor comprising;A generator configured to compress luminance component and chrominancecomponents of an input image to generate low-resolution images; Ahigh-resolution image generator configured to generate, from the inputimage, a high-resolution image that is higher in resolution than theinput image; a separator configured to separate the low-resolution imageof luminance component generated by the generator into a texturecomponent image and a frame component image and separate thelow-resolution image of chrominance components generated by thegenerator into a texture component image and a frame component image; Areference image generator configured to expand the texture componentimage of luminance component separated by the separator to generate areference image, wherein; a texture generator configured to receive thetexture component image of luminance component generated by thereference image generator and the frame component images of luminancecomponent and chrominance components separated by the separator andgenerate texture component highly similar to each of attention points ofan image to be output; and A combiner configured to combine the texturecomponent generated by the texture generator with the high-resolutionimage generated by the high-resolution image generator to generate anoutput image.
 3. The image processor of claim 1, further comprising aprevention module configured to prevent blur in the high-resolutionimage generated by the high-resolution image generator, wherein thecombiner is configured to combine the texture component with thehigh-resolution image where blur is prevented by the prevention module.4. The image processor of claim 1, wherein the image processor isconfigured to be mounted on an electronic device.
 5. The image processorof claim 4, wherein the electronic device is a television receiver. 6.An image processing method comprising: compressing, by a generator, animage of chrominance components except luminance component of an inputimage to generate a low-resolution image; generating, by ahigh-resolution image generator from the input image, a high-resolutionimage that is higher in resolution than the input image; separating, bya separator, the low-resolution image into a texture component image anda frame component image and separating , by the separator, the image ofluminance component of the input image into a texture component imageand a frame component image; receiving, by a texture generator, thetexture component image of luminance component and the frame componentimages of luminance component and chrominance components and generating,by the texture generator, texture component highly similar to each ofattention points of an image to be output; and combining, by a combiner,the texture component with the high-resolution image to generate anoutput image.
 7. The image processor of claim 2, further comprising aprevention module configured to prevent blur in the high-resolutionimage generated by the high-resolution image generator, wherein thecombiner is configured to combine the texture component with thehigh-resolution image where blur is prevented by the prevention module.8. The image processor of claim 2, wherein the image processor isconfigured to be mounted on an electronic device.
 9. The image processorof claim 8, wherein the electronic device is a television receiver.